Stromberg Carb Leaks

[4390]

Letting the carb run out of fuel or just letting the carb run low of fuel depends on your flying habits. Letting the carb sit too long without fuel will harden the gaskets. If you don't fly on a regular basis it might not be a good idea to run the bowl dry.

[8357]

Do any of you have a current source for the neoprene needle and matching seat for the Stromberg? Thanks!

[6643]

Try Fresno Airparts. Be aware, there were some counterfeit neoprene needles, which is probably what gave them the bad name in the first place. There is no new production of neoprene needles for that carb.

[8357]

Thanks! Like most, I'm running the stainless needle with matching seat. Still weeps even after new install and or lap. it'll hold awhile, but not long term even after overhaul. Yup... turning fuel valve to off at stop. Only running 100ll.

[6643]

Yup... turning fuel valve to off at stop.

You should be doing that anyhow. All float valves eventually fail or get replaced prophylactically. Gravity, on the other hand, has proven to be 100% reliable since the beginning of time.

[6729]

It is my experience that if you use auto gas you will have fuel leaks. One, the auto gas will seep by the needle and seat no matter what you do. Replace the needle and seat, lap it all you want and it will still leak. Second, the gas you see pouring out on shutdown is not coming from the carburetor. It is gas draining back down through the throat of the carb. It is gas that has pooled in the intake manifold above the carb but below the cylinders. The vacuum and airflow in the manifold keeps it suspended in that area. When you shutdown it all drains out back through the carb. If you wait it will quit dripping without shutting off the fuel. Auto fuel does not appear to vaporize like avgas. I had these problems and avgas pretty much solved them for me. Not to mention my exhaust pipes burn white instead of sooty black now. I do shut off the fuel to prevent to blue stains on the bottom of the cowling however.